Clock setting mechanism



April 1952 M. WEBER CLOCK SETTING MECHANISM Filed 001;. 22, 1947 Patented Apr. 22, 1952 CLOCK SETTING MECHANISM Max Weber, Geneva, Switzerland Application October 22, 1947, Serial No. 781,296 In Switzerland September 29, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires September 29, 1965 1 Claim. 1

The present invention relates to a clock in which the movement is considerably simplified by the use of a new type of reduction gear. 1

According to the invention the movement ha reduction gear for the reduction of the rotary speed of the second-hand spindle transmitted to the minute-hand spindle which is co-axially mounted on the former, and of the rotary speed of the minute-hand spindle transmitted to the hour-hand spindle which is co-axially mounted on the minute-hand spindle.

For driving the clock movement it is of advantage to use a synchronous motor by which the second-hand spindle is actuated.

The clock may be designed as an electric alarmclock, the circuit for the operation of the acoustic alarm device being closed by a contact device formed by two contact rings arranged concentrically to each other and a wedge contact dropping between said two contact rings and adjustable in relation to a release organ rigidly mounted on the hour-hand spindle.

The electric alarm-clock can be provided with a built-in light, preferably in the form of a neon tube located on the periphery of the dial.

The electric alarm-clock may moreover be combined with an electric cigarette-lighter.

In the drawing a preferredembodiment of the invention is illustrated as follows:

Fig. 1 is a longitudinal section through the reduction gear and the alarm contact device of an electric alarm-clock, and

Fig. 2 is a side elevation of the electric alarmclock.

In the-illustrated embodiment the clock movement is driven by a synchronous motor, not shown in the drawing, in such a way that the second-hand spindle I, together with the second hand 2, performs one revolution per minute. On

the second-hand spindle l the hollow spindle 3 of the minute-hand 4, and on this hollow spindle 3, the hollow spindle 5 of the hour-hand E, are loosely mounted so as to be rotatable. At the rear end of the minute-hand spindle 3 of cog-wheel l, and at the rear end of the hour-hand spindle 5 a cog-Wheel 8 are mounted. In addition thereto a bush 9 is rotatably mounted on the hourhand spindle while a cog-wheel ID and a cogwheel II are rigidly mounted on bush 9. A bracket I2 is fastened to the second-hand spindle I, which bracket carries at its free end a spindle I3 and a planet wheel 14 rotatably mounted on the latter. This planet wheel meshes with the cog-wheel l and cog-wheel H. The cog-wheel 7 has 60 teeth while the cog-wheel H has only 59 2 teeth. If the cog-wheel II is held immovably and the second-hand spindle I is rotated through 360, the planet wheel I 4 is rolled around the periphery of the cog-wheel l I and imparts to the cog-wheel 1 (minute wheel) an advance by one tooth, i. e. by ,4 its circumference. In the same way as to the bracket I2, a spindle I5 is also fastened to the minute wheel I, on which spindle a planet wheel I6 is rotatably mounted. The latter engages the cog-wheels 8 and Hi. The cog-wheel B has 24 teeth while the cog-wheel ID has 22 teeth. If the cog-wheel I0 is held immovably and the planet wheel I6 rolled around the cog-wheel ID by rotation of the minute-wheel I through 360, the cog-wheel 8 (hour-wheel) is advanced by two cogs, i. e. by one-twelfth of its circumference. On the bush 9 a cog-wheel ll of a mitre gear ll, 18 is also rigidly mounted. By turning a setting knob 20 mounted on a spindle I9 of the cog-wheel l8 outside the alarm clock casing (Fig. 2) the hands 4 and 6 can be set. Since the minutewheel 1 and the hour-wheel 8 are adjusted by the rotation of the interconnected wheels II, II and I0 they cause the planet wheels l4 and [6 to rotate in opposite directions. In a plate 2| rigidly mounted in the alarm-clock casing, the bush 9 is rotatably mounted. By the friction disc 22 and the spring disc 23, however, bush 9 is held motionless in relation to the plate 2| so that the drive of the clock cannot move the cog-wheels ID and H which are rigidly mounted on the bush 9. In setting the hands by means of the mitre gear this friction is overcome. An insulating plate 24 is firmly secured to the front of the plate 2| by means of screws 25. To this insulating plate two insulated contact rings 26 and 28 are secured by means of countersunk screws or rivets 21 and 29. The contact rings are of difi'erent diameter and concentric, and are connected by conductors to screw-terminals 30 and 3|, which lie in the circuit of an electric alarm device. By insertion of a wedge contact 43 in the space between the two contact rings the circuit is closed and the alarm rings. The release device for closing the contact device has a sleeve 32 mounted so as to be axially displaceable on the hour-hand spindle 5, said sleeve passing through the dial 33 and carrying at its foremost extremity the hand 34 which indicates the time for which the alarm is set. Also on the hour-hand spindle 5 a ring 35 is fixed behind the sleeve 32 by means of a screw 36, said ring being provided with a release notch 31. A spring 38, which abuts on one hand against the dial 33 and on the other hand against a collar 39 on the sleeve 32, tends to press the sleeve 32 against the ring. A pin 40 projecting beyond the rear extremity of the sleeve 32, bears against the ring 35 under the action of the spring 38 and, upon passing the release notch 31 as a result of the rotation of the hour-hand spindle with the ring 35, drops into said notch 31. At the rear end of the sleeve 32 a cog-wheel 41 is mounted which carries the insulated wedge contact 43 insulatedly mounted in the pin 42, said wedge contact 43 connecting the interruptor contact rings 26 and 28, and thus closing the circuit operating the alarm-device when the pin 40 drops intov the release notch 31. A cog-wheel 44, which engages with the cog-wheel 4| so as to form a mitre gear for setting the alarm hand 34, is mounted on a spindle 45 which carries a setting alarm-hand 3.4;.

Spindle 45 carries a setting knob 46. outside the alarm-clock casing. A neon tube is located around the periphery of the dial 33 for illuminating the dial permitting the alarm-clock to be-used as a bed-side lamp; The alarm-clock casing; 41' is of streamlined design,.its lid being provided with ventilation slots150 in' the socket 48' for the glass 49 to prevent overheating: of the alarm-clock casing by the neon tube. 5| designates-aswitch for switching'on the alarm.. The wing 52' may be designed as a. switch. for the switching on and-off. of the neon tube. The electric cable is introduced-through the basez53 of the alarm-clock casing, so that the alarm-clock maybe-connected by a plug to a lighting mains socket.

The operation ofthe. alarm clock. is asfollows: When the second-hand. spindle l rotates, the planet. wheel [4 turns with it and rolls along the peripheryof the frictionallyarrested cogwheel. I |,,so, that during-a. revolution of 360 theminute-wheel 3 i'sqturnedionly k of its circumference owing-to the. difference in the number of teeth, that'is to say that the minute-hand 4' is turned through a division on the dial correspondingtooneminute whilethe second-hand rotates through 360". During: one complete revolution of the minute-wheel I. the planet. wheel I3 is rolled along the'peri'phery'of the frictionally held cog-wheellll, the hour wheel 8 being" turned, onetwelfth of. its circumference owing to the difference in the number of. teeth. In other words, the hour-hand rotates for one complete revolution of the minute-hand, to an extent correspond?- ing to one hour on the dial.

In putting the clock back or forward by the rotary knob 20 and the mitre: gear I! and I8, the planet-wheels l4 and: 16' are rolled along the peripheries' of the cog-wheels l0. and II. respectively 4 by the rotation of the cog-wheels I0 and II during a complete revolution of the cog-wheel H, the minute and hour wheels being thus turned forwards or backwards in accordance with the gear ratio. The hands can be regulated without disturbing the running of the clockin any way.

The reduction gear described can readily be used for spring-actuated clocks.

While a preferred embodiment of the invention is herein disclosed, it is to be understood that some changes may be made in the arrangement, construction and combination of the various parts of my invention, and it is my intention to cover by my claim such changes as may reasonably be included within the scope of the invention.

I claimas my invention:

In a clock, train, in combination, a second hand shaft, a hollow minute hand shaft coaxially mounted on said second hand shaft, a hollow hour hand shaft coaxially mounted on said minute hand shaft, a bracket fixedly mounted on said second hand shaft, a rotary planetary pinion stud-mounted on saidbracket, a spur wheel fixedly mounted: on said minute hand shaft. and meshing with said planetary pinion, a second rotary planetary pinion stud-mounted on said spur wheel, a second spur wheel fixedly mounted on said hour hand shaft and meshing, with said second planetary pinion, a sleeve loosely mounted on said hour hand shaft, a third: spur wheel fixedly mounted on said sleeve andmeshing with said first planetary pinion, a fourth spur wheel fixedly mounted onsaid sleeve and meshing with said second planetary pinion, friction means adapted to prevent rotation of: said sleeve. under normal operative conditions, the numberjof teeth of said third and fourthspur wheels slightly-differing from the number of teeth of said firstand second spur wheels,.the ratio being such as" to obtainv the proper reduction between the second, minute, and hour hand shafts, and means for rotating said sleeve against action of. said friction means for setting the hand shafts.

MAX WEBER.

REFERENCES. CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number. Name Date 1,813,942 Malles July 14,. 1931 2,026,368 Warren Dec. 31, 1935 2,198,632 Mullan Apr. 30, 1940 

